| Ultimate tensile strength (2) | Ultrathin films (1) | Ultraviolet devices (1) |
| Ultraviolet visible spectroscopy (1) | unclassified drug (1) | Underlying surface (1) |
| Uniaxial deformation (1) | Uniaxial tensile test (1) | Unloading (1) |
| UV irradiation (1) | UV sensor (1) | UV-vis spectroscopy (1) |